Running of elongated pipe in a well



Se t. 2, 1969 E. R- GENOIS ET AL 3,464,496

RUNNING OF ELONGATED PIPE IN A WELL Filed Sept. 30, 1968 2 Sheets-Sheet 1 (w s J\ R WSE .vmn. V I. N W 0 8 N 0M M0 H E v 3,464,496 RUNNING OF ELONGATED PIPE IN A WELL Edmond R. Genois, New Orleans, La., and Thomas W.

Childers, Woodland Hills, Calif., assignors to Esso Production Research Company Continuation-impart of application Ser. No. 607,713, Jan. 6, 1967. This application Sept. 30, 1968, Ser. No. 767,048

Int. Cl. E21b 23/04 U.S. Cl. 166315 12 Claims ABSTRACT OF THE DISCLOSURE Elongated pipe is run into a well conduit, a portion of which is curved, by exerting fluid pressure against pump tools attached to the elongated pipe. The elongated pipe has suflicient rigidity and strength to support its weight and maintain its elongation. When the elongated pipe passes through the curved portion of the conduit it is deformed past its yield point, yet may be reused.

Cross-reference to related application This application is a continuation-in-part of Ser. No. 607,713 filed Jan. 6, 1967, for Edmond R. Genois and Thomas W. Childers entitled Running of Elongated Pipe in a Well, and now abandoned.

BACKGROUND OF THE INVENTION Field of the invention The present invention is concerned with the running of an elongated pipe in a well. More particularly, the invention is concerned with running a tubing extension member in a well. In its more specific aspects, the invention is concerned with running an elongated tubing extension member into a well having a conduit in which at least a portion of which is curved, such as a well completed on ocean floor.

Description of the prior art It is known to run tubing extensions into a well on a wire line with fluid pressure. It is also known to run flexible tubing extensions into a well by fluid pressure exerted thereagainst. Coiled tubing extending from a reel at the earths surface into a well has been pumped down a well with fluid pressure exerted thereagainst. Segmented and angularly articulated pump tools have been run into wells having curved portions. However, such operations have been attended with problems since when flexible pipe was used, the pipe would corkscrew or kink because of its flexibility. Segmented and angularly articulated tools drag against the wall of the well and are expensive to build and are subject to leaks due to wear and abrasion. Heretofore, it wasnt known that these problems could be avoided by running a free, relatively rigid, elongated pipe under compression through curved lines with fluid pressure.

Prior art considered in preparing this application is as follows:

U.S. PATENTS SUMMARY OF THE INVENTION The present invention may be briefly described as a method for running an elongated section of pipe in a atent O well provided with a well conduit at least a portion of which is curved or deviated, particularly at the wellhead such as with a radius bend. 'Ihe elongated pipe must travel through the well conduit and through the curved portion thereof. The elongated pipe has sufficient strength to support its weight in the conduit and has a free first lead end and a free second tail end. The elongated pipe has suflicient rigidity and strength to maintain substantially its elongation as it travels through the well conduit including the curved portion.

In the practice of the present invention, the free elongated pipe is introduced into the well conduit such that both the lead end and the tail end are within the well conduit. Thereafter, sufficient fluid pressure is exerted against retrievable pump tools attached to the elongated pipe to force the pipe through the well conduit including the curved portion. The fluid pressure is preferably exerted against the tail end of the elongated pipe to cause it to travel through the well conduit; however, the fluid pressure may be exerted against pump tools on the lead end of the elongated pipe. Particularly, as the elongated pipe is retrieved from the well, pump tools on the free second end are on the lead end with respect to tubing motion. The elongated pipe is run into the well and may be landed in the well conduit at any particular point that may be desired, but preferably the elongated pipe is landed in the lower end of the well conduit to extend therefrom and to increase the effective length of the well conduit.

The well conduit may have a second conduit connected to it at its lower end through which fluid pressure may be exerted through the elongated pipe against pump tools attached to the pipe to retrieve the elongated pipe from the well. The pressure may be exerted through the well conduit or through the separate well conduit.

ADVANTAGES AND UTILITY OF THE INVENTION The present invention is quite advantageous and useful in that a free elongated section of steel pipe, which may be termed a tubing extension member, may be run into a well having a curved portion by using fluid pressure alone. Heretofore, it was unknown that pipe having sufficient rigidity and strength to support its own weight in the conduit, and having required burst and collapse characteristics, had suflicient flexibility to allow it to be run into a well under pressure through a curved portion of the well conduit. The physical characteristics of such pipe as to rigidity, strength, burst and collapse are well known, but it was not known that such pipe having "diameters from about 0.5 inch to about 2 inches could be run into a well through a curved flow line by fluid pressure and be deformed beyond its minimum yield point and yet be reused. Heretofore, the only recourse had been to use flexible pipe but such flexible pipes were not sufficiently rigid and were so flexible that when running same into a well, frequently the flexible pipe kinked or corkscrewed. It was also thought heretofore that it was necessary to maintain tension on an elongated pipe as it was being run into a well because, otherwise, it was thought that such pipe under compression would corkscrew or kink.

Likewise, the prior art has employed segmented or articulated pipe but such segmented or articulated members dragged against the Walls of the well conduit and are expensive to construct, subject to leaks, wear and the like, even though the segmented or articulated tools are designed to present minimum wear surface against the walls of the conduit which they traverse.

3 CHARACTERISTICS OF THE FREE ELONGATED SECTION OF PIPE AND THE BEND As stated before, the metal pipe should be from about 0.5 inch to about 2 inches in diameter and may have a minimum yield of about 30,000 p.s.i. although a minimum yield of about 50,000 p.s.i. is preferred. However, stronger steel pipe may be used with yields up to about 100,000 p.s.i. Ordinarily metal pipe having a yield from about 30,000 to about 100,000 p.s.i. may be used as the free elongated section. The burst and collapse characteristics of the free elongated section may suitably be at least 1,000 p.s.i. each, but may range higher up to about 5,000 p.s.i. or higher.

The radius bend at the wellhead is suitably about feet, but may range up to 20 feet. The smaller radius bends are preferred, in the range preferably from about 5 to about feet, although a radius bend of about 3 feet may be used. Thus, a range of about 3 to about feet radius bend may be used.

It is to be pointed out that the free elongated section when used in the present invention is deformed past its yield point and takes a permanent set which is only partially removed as it moves into a straight section of the conduit through which it is run. Thus, a free elongated section having a 0.75 inch 0D. in passing through a 2 inch I.D., five foot radius loop may be deformed past its yield point and take a permanent set which in an unrestrained condition may assume the shape of a circle of approximately feet radius and yet the section may be reused many times without seriously reducing its resistance to burst and collapse while being straightened sufficiently each time in a straight section to be effective.

BRIEF DESCRIPTION OF THE DRAWING The present invention will be further described by reference to the drawing in which a best mode and embodiment are described and in which FIG. 1 is a sectional view of a well drilled on water bottom of a body of water illustrating the present invention; and

FIGS. 2, 3 and 4 are further showings of the practice of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS IN CONJUNCTION WITH THE DRAWING Referring now to the drawing in which identical numerals will designate identical parts, numeral 11 designates a well drilled from the sea floor 12 to penetrate a producing formation designated as 13. The well 11 may have a suitable casing 14 arranged therein and a plurality of well tubing strings 15 and 16, the tubing strings 15 and 16 being interconnected by a cross-over connection 17 adjacent their lower ends. The well 11 is closed on water bottom with a wellhead 18 from which curved flow lines 19 and 20 connected to and forming part of the wellhead extend. The curved flow lines 19 and 20 may extend to shore or to a remote platform 21 on which production facilities such as storage tanks (not shown) and the like are arranged. The remote platform 21 is arranged above the water level 22 a sutiicient distance to be substantially out of the reach of wave action.

In the practice of the present invention, an extension pipe generally designated 23 has releasably connected to its free tail end 25 a running tool generally designated as 28. Running tool 28 is provided with pump cups 30 for pumping the tool 23 into the well and pump'cups 31 for pumping the tool 23 out of the well (see FIGS. 2-4). The two units 23 and 28 are inserted into the flow line 19 through a suitable lubricator (not shown) on the remote platform 21 and fluid pressure is exerted against pump cups 30 of the running tool 28 to cause the extension pipe 23 to be moved through the flow line 19, through the curved section 26 at the wellhead and down through the tubing 15. The flow line 20, as illustrated, is also provided with a curved section 27 which connects into tubing string 16. The running tool is jointed together so as to traverse the curved sections of the pipe it travels through.

As shown in FIG. 2, the extension pipe section 23 having traversed the curved section 26 down through the tubing 15 may land in a landing nipple such as 29 of the usual construction well known in the art and be locked in place and packed 01f by an extension hanger 32 such that the extension pipe member 23 projects with its lower end 24 extending from the lower end of the tubing 15. After retrieving running tool 28, it may be desirable to circulate fluids, such as cement slurries, acid, oil-water emulsions, perforating fluids and the like, through the tubing 15 and the extension pipe section 23, and out through tubing 16, as shown in FIG. 3.

When it is desired to retrieve the extension pipe section 23, retrieving tool 28A is run in and attached to tool 23 and fluid pressure is then exerted through the flow line 20 and tubing 16 through cross-over connection 17 and through the extension pipe section 22, against pump cups 31, to cause the extension to again travel up well tubing 15 through the curved portion 26 and thence vthrough flow line 19 back to the remote platform 21. In this manner, the extension pipe section 23 may be introduced and forced into the well, then retrieved by the use of fluid pressure alone (FIG. 4). It is quite unobvious and unexpected that pipe having the strength and rigidity of the pipe employed in the present invention and can be introduced into a well in accordance with the present invention by the use of fluid pressure alone without modifying the pipe as thought necessary in the prior art.

The invention has been demonstrated in which O.D., /8" OD. and 1'' OD. steel tubes have been run into a well having a curved flow line and out of the well successfully. In one example, nineteen hundred feet of the /4" steel tube have been successfully pumped through the flow line around the loops into and out of the well using through flow line pump tools. In other operations, one hundred foot sections of the A3 OD. and 1" OD. steel tubes have been successfully run in and out of the well. The lengths of the pipe sections may vary from about 10 feet to about 2,000 feet, although greater lengths may be used. A length of about 500 feet is easily handled. Lengths from to about 2,000 feet may be preferred in some instances.

It was entirely unexpected and unobvious that unsegmented pipe sections could be run into a well since heretofore it was thought that special flexible extension pipe members or flexible couplings were needed. Moreover, the steel tubing employed in the present invention has excellent wear resistant characteristics and is quite inexpensive. For example, the steel tube costs approximately $.10 per foot, whereas other pipe extensio members of the prior art of a flexible nature cost up to $25.00 per foot. Moreover, the use of continuous pipe extension sections reduces the possibility of leakage in that it is unnecessary to provide special flexible couplings. The only coupling needed are two conventional tubing couplings which are employed to connect the first end of pipe to a guide-test plug 31 and the second end to an extension hanger 28. While steel pipe has been used in the practice of the present invention, any other metal which was sufficient rigidity and strength to support its own weight and yet is sufficiently ductile may be employed. As an example thereof may be mentioned aluminum pipe.

The nature and objects of the present invention having been completely described and illustrated and the best mode and embodiment contemplated thereof set forth, what we wish to claim as new and useful and secure by Letters Patent is:

1. A method of running a free elongated section of open ended metal pipe having a diameter within the range from about 0.5 to about 2 inches in a well provided with a well conduit at least a portion of which is curved at the wellhead with a radius bend of about 3 to about 20 feet through which said elongated section must travel, said elongated section having sufiicient strength to support its weight, a minimum yield of about 30,000 p.s.i., and having a free first lead end and a free second tail end, which comprises:

introducing said elongated section into said well conduit such that both the lead end and tail end are both within said well conduit; and exerting sufiicient fluid pressure against said elongated section to force said elongated section through said well conduit including said curved portion and deform said elongated section past its yield point;

said section having sufficient rigidity and strength to maintain substantially the elongation of said section as it travels through said conduit including said curved portion.

2. A method in accordance with claim 1 in which fluid pressure is exerted against the tail end of said elongated section.

3. A method in accordance with claim 1 in which the elongated section is landed in said well conduit and thereafter retrieved by again exerting fluid pressure against said elongated section to force said elongated section through said well conduit including said curved portion.

4. A method in accordance with claim 3 in which fluid pressure is again exerted against the tail end of the elongated section.

5. A method in accordance with claim 3 in which the elongated section is landed in the lower end of the well conduit to extend therefrom into the well.

6. A method in accordance with claim 3 in which fluid pressure is again exerted against said elongated section through a separate fluid conduit communicating with the lower end of said well conduit.

7. A method in accordance with claim 1 in which the fluid pressure is exerted through said well conduit.

8. A method in accordance with claim 1 in which the elongated section has a length within the range from about 100 to about 2,000 feet.

9. A method in accordance with claim 1 in which the free elongated section has a yield point within the range from about 30,000 to about 100,000 psi.

10. A method in accordance with claim 1 in which the free elongated section has burst and collapse characteristics each within the range from about 1,000 to about 5,000 psi.

11. A method in accordance with claim 1 in which the radius bend is within the range of about 3 to about 7 feet.

12. A method in accordance with claim 1 in which the free elongated section has:

(a) a yield point within the range from about 30,000

to about 100,000 p.s.i.;

(b) burst and collapse characteristics each within the range from about 1,000 to about 5,000 p.s.i.; and the radius bend is within the range from about 3 to about 7 feet.

References Cited UNITED STATES PATENTS 2,805,718 9/1957 Tausch 16646 X 3,003,560 10/1961 Corley et al 166-.5 X 3,020,955 2/1962 Tausch 166-156 X 3,312,282 4/1967 Yetman 166-46 3,346,045 10/ 1967 Knapp et al. 16646 X 3,363,693 1/1968 Bohlmann l66---45 3,367,421 2/ 1968 Raulins 166-153 OTHER REFERENCES Gatlin, Carl, Petroleum Engineering: Drilling and Well Completions. Englewood Clifis, N.J., Prentice-Hall, 1960, pp. 142 and 143.

Uren, Lester C., Petroleum Production Engineering: Oil Field Development, New York, McGraw-Hill, 4th Ed., 1956, pp. 413 and 414.

CHARLES E. OCONNELL, Primary Examiner J. A. CALVERT, Assistant Examiner US. Cl. X.R. 1'6 6-1 5 3 

